METHODS OF VENTILATION. 283 



anything in the way of improving our present systems, or 

 discouraging the application of new mechanical inventions to 

 aid the practical operations of horticulture, we would say that 

 some of these methods lately brought into notice may be 

 justly compared to the putting of extra wheels to a carriage, 

 increasing the rattling and complexity of the machine, but add- 

 ing neither to the strength of the structure nor the rapidity of 

 its course. 



